Hydrometallurgical solubilizer with selective electroplating mechanism

ABSTRACT

A CONTAINER FOR CONDUCTIVE SOLUTION IS DIVIDED INTO A FIRST COMPARTMENT AND A SECOND COMPARTMENT BY AN INERT PERMEABLE BARRIER. THE SOLUTION IS ELECTROCHEMICALLY ACTIVATED TO PRODUCE AND CONTROL THE PH OF AN ACIDIC SOLUTION WITHIN THE FIRST COMPARTMENT AND A BASIC SOLUTION WITHIN THE SECOND COMPARTMENT. PULVERIZED ORE IS DEPOSITED WITHIN THE ACIDIC COMPARTMENT AND REACTS THEREIN WITH THE ACID TO SOLUBILIZED THE METALS AND MOSTE METAL COMPOUNDS CONTAINED WITHIN THE ORE. THE SOLUBILIZED METAL COMPOUNDS ARE CARRIED THROUGH THE BARRIER INTO THE BASIC COMPARTMENT BY IONIC FLOW AND FLUID FLOW. A PLURAITY OD METAL PLATES ARE LOCATED WITHIN THE BASIC CHAMBER FOR   PLATING OUT A SELECTED ONE OF THE METALS AS DETERMINED BY THE CHEMICAL COMPOSITION OF THE SOLUTION AND THE VOLTAGE DROP ACROSS EACH OF THE PLATES.

United States Patent O 3,788,965 HYDROMETALLURGICAL SOLUBILIZER WITH SELECTIVE ELECTROPLATING MECHANISM Wilmar G. Holsinger, Phoenix, Ariz., assignor to 2C-2B Corporation, Phoenix, Ariz- Filed Apr. 7, 1972, Ser. No. 242,086 Int. Cl. B011; 3/00, 3/10 US. Cl. 204-234 12 Claims ABSTRACT OF THE DISCLOSURE A container of conductive solution is divided into a first compartment and a second compartment by an inert permeable barrier. The solution is electrochemically activated to produce and control the pH of an acidic solutlon within the first compartment and a basic solution within the second compartment. Pulverized ore is deposited within the acidic compartment and reacts therein with the acid to solubilize the metals and most metal compounds contained within the ore. The solubilized metal compounds are carried through the barrier into the basic compartment by ionic flow and fluid flow. A plurality of metal plates are located within the basic chamber for plating out a selected one of the metals as determined by the chemical composition of the solution and the voltage drop across each of the plates.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to ore refining, and more partrcularly to hydrometallurgically solubilizing the metals and most metal compounds in ore and electroplating same.

Description of the prior art Pyrometallurgical smelting of ore is a very expensive and ineflicient series of operations and many multi-million dollar smelters are experiencing operational problems due to this inefficiency and the resultant production of pollutants.

The following is a discussion of some of these problems as encountered in the smelting of copper, and are exemplary of the problems associated with the smelting of other metals.

In the United States, uncombined native copper is found, but the most productive ores are the various forms of the sulfides, such as chalcopyrite (CuFeS- boronite (CuFeS and chalcocite (Cu S).

The process by Which copper is smelted depends on the nature of the ore and the impurities in it. Thus, native copper may be treated by a purely mechanical process. However, 70% of the ores mined in this country are sulfides which usually contain, in addition to the copper sulfide, large amounts of sulfide of iron, silica and quantities of other impurities.

The smelting of sulfide of copper is divided into four basic steps or stages, these being: concentration, formation of a copper matte, conversion of the matte to free copper, and refining of the product.

As the crude ore comes from the mine it may contain as little as .3% to 2% of the actual metal, consequently a preliminary process of separation or concentration is almost imperative. This preliminary concentration may be accomplished by a chemical flotation process which is highly effective in the concentration of copper sulfide ores and in the separation from mixtures of mineral substances. This preliminary separation results in a concentrated ore containing 12% to 35% copper by weight, which also contains iron and sulfur compounds.

The next two steps are the forming of the copper matte and its conversion into free copper, and these steps include heating of the ore to oxidize the sulfides and separate the copper from the iron. The end product, free copper, is generally 98% to 99% pure.

3,788,965 Patented Jan. 29, 1974 The last step is the refining of the copper and is normally accomplished by electroplating.

The hereinbefore described steps in the smelting of copper ore not only consume great quantities of oil or natural gas for the heating steps but produce great quantities of sulfur and noxious gasses which escape into the atmosphere. Polluting of the atmosphere with sulfur dloxide and other pollutants has recently caused great concern and large amounts of money are now being expended for pollution control devices which, thus far, have not proved economically feasible.

Therefore, the need exists for a pollution free device for refining ore.

SUMMARY OF THE INVENTION In accordance with the invention, a hydrometallurgical solubilizer and an electroplater are combined into an ore handler for inexpensively extracting metals from the ore with the production of no pollutants.

The ore handler 0f the present invention includes a container formed of inert material which is divided into two compartments by an inert permeable barrier. A conductive solution, formed of suitable compounds as determined by the particular metal to be processed, is placed within the container. A positive DC potential is applied to a non-metallic anode in the first one of the compartments and a negative DC potential is applied to a metallic cathode in the second one of the compartments. This results in an electrolysis of the solution which produces an acidic solution in the first compartment and a basic solution within the second compartment. The pH of the acidic and basic solutions are regulated by causing the conductive solution to flow through the container at a controlled rate.

Pulverized ore is deposited within the first compartment where it reacts with the acidic solution to solubilize metals, and many of the metal compounds contained in the ore. Ionic flow and the fluid flow will cause the solubilized metals and metal compounds to pass through the barrier into the basic compartment. The chemical composition of the conductive solution will cause predetermined ones of the solubilized metals to precipitate and will allow others to remain in the solution.

The cathode in the basic compartment is of special construction to accomplish the electroplating function of the ore handler of the present invention. The cathode includes a plurality of removable metallic plates having a zig zag flow path for the conductive solution formed therethrough. The plate which is located furthest from the barrier has the negative DC potential applied thereto. The number of plates employed determines the voltage drop across the plates, and the voltage drop determines which of the solubilized metals. will be electroplated onto the plates.

By selecting the proper conductive solution, and by adding or removing plates from the cathode to provide a particular voltage drop, the apparatus of the present invention can be implemented to electroplate many metals and metal compounds.

Accordingly, it is one object of the present invention to provide a new and useful pollution free apparatus for inexpensively refining ore.

Another object of this invention is to provide a new and useful apparatus for solubilizing metal and most metal compounds from ore and plating out a desired one of the solubilized metals.

Another object of the present invention is to provide a new and useful apparatus for refining ore which solubilizes metal and most metal compounds and is configurable to plate out a desired one of the solubilized metals.

Yet another object of this invention is to provide an ore handling device of the above described character which provides recirculation and reclaiming of the fluids employed therein.

The foregoing and other objects of this invention, as well as the invention itself, may be more fully understood when read in conjunction with the following drawmgs.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematically illustrated plan view of the hydrometallurgical solubilizer with the electroplating mechanism showing the various features of the present invention;

FIG. 2 is a schematically illustrated side view of the apparatus of the present invention;

FIG. 3 is a sectional view taken on the line 3-3 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly to the drawings, a container is illustrated which is formed of a suitable inert material such as polyvinyl chloride (PVC). The container 10 is preferably an elongated tank-shaped structure. However, the shape illustrated should not be considered as a limitation to the invention.

A conductive solution 18 is utilized in the ore handling device and is subjected to electrolysis therein. As will hereinafter be described in detail the combination of the chemical composition of the solution, the electrolysis and the novel structure enables the device to extract metal and most metal compounds from pulverized ore by solubilization. This unique combination is also capable of electroplating a desired one of the solubilized metals and conditions the remaining metals for subsequent processing.

The container 10 is divided into two chambers or compartments 12 and 14 by an inert permeable barrier 16. The barrier 16 may be formed of PVC or any other suitable inert material. A preferred fabrication technique is to employ strands of PVC which are tightly woven so as to result in the barrier having a mesh of 100 or finer openings. A barrier having a 100 mesh will work in the apparatus of the present invention, but it has been determined that a mesh of between 150 and 300 is ideal.

A supply system is coupled to the container 10 for providing a continuous flow of the conductive solution 18 into the first chamber 12 and out of the second chamber 14. In the preferred embodiment the supply system 20 is employed as a recirculating and reclaiming system so that the conductive solution 18 and the compounds forming the solution are reusable.

The system 20 includes an outlet 22 coupled to the chamber 14 from which a suitable pump 24 draws the solution 18, and delivers it to a series of processing tanks 26. The processing tanks 26 may be either settling tanks or electroplating mechanisms as required by the type of metal to be stripped from the solution and the desired end product.

The output from the last of the tanks 26 delivers the solution 18, from which the solubilized metals and metal compounds have been stripped, to a make-up reservoir 28. The make-up reservoir may be employed for the original forming of the conductive solution and may also be used to make up any losses which may gem in the system from leakage, evaporation, and the The supply system 20 may also be employed to periodically supply pulverized ore to the first chamber 12 of the container 10.

The solution 18 within the make-up reservoir 28 is delivered therefrom to a flow switching solenoid 30. The solenoid 30 will selectively route the solution 18 either to an ore supplying line 32 or to a by-pass line 34.

When the solenoid 30 is energized to direct the solution 18 into the ore line 32, it is delivered to a slurry tank 36 wherein the conductive solution 18 is combined with the pulverized ore.

Ore pulverized in accordance with well known techniques such as by a ball mill (not shown) may be supplied to the slurry tank 36 by any convenient method. The conductive solution containing the pulverized ore is routed from the slurry tank 36 through a suitable pump 38 to a flow control valve 40 from which it is routed to the chamber 12 of the container 10. 7

When the solenoid 30 is energized to route the conductive solution from the make-up reservoir 28 to the by-pass line 34, the solution is delivered directly to chamber 12 of the container 10 through a pump 42 and a flow control valve 44.

During normal operation of the ore refining device of the present invention, a continuous flow of the conductive solution 18 through the by-pass line 34 is maintained at a predetermined flow rate by proper regulation of the valve 44. At predetermined intervals the solenoid 30 is energized so as to deliver the ore containing slurry into the chamber 12. The parameters which determine the flow rate and the ore delivering intervals will be hereinafter described.

The chamber 12 is provided with an anode 46 positioned therein which is formed of a non-metallic conductive material such as carbon. The chamber 14 is provided with a cathode means 48 positioned therein which may be formed of a metallic conductor such as iron.

A DC potential is applied to the electrodes 46 and 48 so that the anions of the conductive solution 18 are attracted to the anode 46 and the cations are attracted to the cathode 48. Thus electrolysis of the solution takes place in the container 10 which forms an acidic solution within the chamber 12 and forms a basic solution within the chamber 14.

An example of the electrolysis process will now be given to show the electrochemical reaction which takes place within the container 10 which results in the formation of the acidic and basic solutions.

For purposes of this example, the electrovalent compound ammonium chloride (NH Cl) is dissolved in a polar liquid H O, the solute is made up entirely of ions of NH CI. Thus, if a DC potential is applied, destruction of the NH Cl ions will occur. This results in the production of free ammonium which will immediately react with the H 0 to form ammonium hydroxide (NH OH). The ammonium hydroxide forms a basic solution and will be located in the vicinity of the cathode means 46. Some of the chloride anions, which are halogens, are released as free chlorine some of which reacts with the H 0 to form hypochlorous acid (HOCl) thus creating an acidic solution in the vicinity of the anode. The halogen, chlorine, is considered as an acid anhydride and will therefore react with water to produce an acid.

This reaction is demonstrated in the following formula:

The electrolysis of the ammonium chloride produces free chlorine which reacts to form the hypochlorous acid as described, however, not all of the chlorine will react in this manner due to ionic equilibrium of the solution. The free chlorine which does not react to form hypochlorous acid must be controlled due to its highly toxic nature. Controlling of the free chlorine will hereinafter be described in detail.

From the foregoing description it may readily be seen that control of the pH of the acidic and basic solutions and the amount of uncombined chlorine produced may be controlled by varying the DC potential and/or by varying the flow rate of the ammonium chloride solution through the container 10. That is, if Weak solutions and little or no uncombined chlorine is desired, lowering the DC potential and/or increasing the flow rate of the solution would accomplish this end. For reasons to be hereinafter described in detail the apparatus of the present invention requires a fairly constant DC voltage, therefore controlling of the flow rate of the solution through the container is provided by the supply system 20.

The method described for the electrolysis of the ammonium chloride would soon result in destruction of the electrodes and contamination of the conductive solution if it were not for the inert permeable barrier 16. The reasons being that the metal which is necessarily employed to form the cathode would be attacked by the chlorine thus forming a contaminant and the non-metallic conductor would also become part of the solution if placed in the vicinity of the negatively polarized conductive solution.

Therefore, it is essential that the inert permeable barrier provides physical isolation of the electrodes and yet permits ionic and fluid flow therethrough. The barrier 16 performs such a function by trapping the free chlorine within the acidic chamber 12 thus preventing it from reaching the cathode means 48. The barrier plus the controlled rate of fiow of the conductive solution will pre- 'vent the negatively polarized solution from reaching the anode 46.

The above described example is merely exemplary of one of the compounds which may be employed in the apparatus of the present invention. As will hereinafter be described in detail, other compounds may be employed.

Since all metals are electro-positive elements by definition, and are therefore able to give off electrons, they may be described as reducing agents. The ability of individual metals to give off electrons depends on the atomic structure of the particular metal, but all metals are capable of giving off electrons. Therefore, by the well known oxidation and reduction process, metallic elements will readily combine with an active electron taking element or compound.

Most metal compounds as they are found in the natural state are not soluble, however, they are generally made up of a metallic element in combination with at least one non-metallic element. The non-metallic portion is generally substitutable, therefore, by the well known process of chemical substitution the non-metallic element may be replaced by another non-metal and thus be changed chemically into a soluble compond.

Some metal compounds are not capable of being changed into soluble compounds thus they are not processable in the ore handler of the present invention. These non-processable metal compounds are those which possess ceramic type structures such as rutile, sapphires, beryl, and the like.

The above described processes of oxidation reduction and chemical substitution are employed in a chamber 12 of the container to solubilize all known metals and metal compounds except those having ceramic type structures.

Therefore, the solubilization process which takes place in chamber 12 changes the metals and metal compounds contained in the ore into metal compound solutes. The ion flow and the flow of the solution 18 through a carrier 16 will cause the metal compound solutes to migrate into chamber 14. Some of these metal compound solutes will remain solubilized while others will immediately precipitate upon contacting and reacting with the basic solution.

It should now be apparent that the chemical composition of the conductive solution will determine the nature of the acidic and basic solutions, and will also determine which solubilized metals will precipitate and which will remain solubilized in the basic chamber 14.

A specific example of the previously described conductive solution and its reaction on a specific metal compound will now be given to facilitate understanding of the solubilization and the ion flow processes.

As hereinbefore described, the conductive solution of ammonium chloride and water is subjected to electrolysis to form hypochlorous acid in the acidic chamber 12 with the production of free chlorine and some hydrochloric acid, and the formation of ammonium hydroxide in the basic chamber 14.

The pulverized ore deposited in chamber 12, by the method previously described or other suitable delivery method, will be stipulated for purposes of this example to contain, among other things, the metal compound chalcopyrite (CuFeS The object of this stipulated example being to chemically substitute for the iron and sulfur portions of the chalcopyrite to form a copper compound which is capable of being solubilized and will not precipitate upon its entry into the basic chamber 14.

Copper molecules of the chalcopyrite will be cleaved from that compound and will readily combine with free chlorine to form cuprous chloride (CuCl) which is a soluble metal compound. The following formula illustrates this reaction:

Upon migration of the cuprous chloride into chamber 14, it will react with the available ammonia to form a copper complex, NH (CuCl)NH It should be noted that this type of bonding is commonly called hydrogen bonding which requires only a small amount of energy to disassociate it into a copper ion which is suitable for plating.

As seen in the above formula which depicted the chemical substitution of the chalcopyrite, the chlorine replaced the sulfur in the original compound and free sulfur is produced which at the ambient temperature of the ore handler of the present invention will precipitate as a solid in the acidic chamber 12. The sulfur will float to the surface and may be skimmed off or otherwise removed and dried into an easily handled commercial product.

The ferric chloride (FeCl is solubilized in the acidic chamber 12 and will pass through the barrier 16 into the basic chamber 14, where it will precipitate as ferric hydroxide 'Fe(OH) and will thus release the three chloride ions for recycling. This reaction produces enough OH radicals to precipitate the iron without using energy and the reaction is illustrated in the following formula:

The above example is exemplary of one type of conductive solution and its effect on a specific metal compound. Further examples will hereinafter be cited to show the versatility of the apparatus of the present invention.

The specific conductive solution and the specific metal compound as described above will be employed extensively hereinafter to facilitate the description of the remaining devices and the description of the electroplating process.

The ferric hydroxide which precipitates immediately upon its entry into the basic chamber 14 will settle to the bottom of that chamber. Thus, that portion of the chamber 14 must be provided with means for removal of the precipitated ferric hydroxide and a drain valve 50 is provided for that purpose. The drain valve 50 may be coupled to a settling tank (not shown) so that the conductive solution may be reclaimed and returned to the system 20.

To perform the electroplating process, a plurality of individually removably mounted metal plates 52 are employed to form the cathode means 48. The plates 52 are positioned in spaced increments with a first plate 52a being closest to the anode 46 and the last plate 5221 being furthest therefrom. The negative DC potential is connected only to the last plate 5211.

As seen best in FIG. 3, each of the plates 52 are provided with an off-center aperture 54 formed therethrough which provides a flow directing means. The plates 52 are positioned so that their respective apertures 54 are alternately positioned adjacent to opposite sides of the container 10. The staggered or misaligned positioning of the apertures 54 in successive plates 52 will cause the conductive solution to follow a zig zag path through the plates in its flow through the container 10. It should be noted that the flow directing means described above is only one example of how the staggered flow path of the conductive solution may be achieved. For example, the apertures 54 of the plates 52 may be replaced with notches (not shown) formed in one of the side edges of each of the plates. Also solid plates (not shown) could be employed and the desired flow path could be achieved by forming channels (not shown) in the side walls of the container 10.

The zig zag flow path will not only cause a relatively even distribution of the conductive solution over the surface of the plates, it will increase the electrical resistance of the solution in that area thereof to a level which is greater than the electrical resistance of the plates 52. By increasing the resistance of the solution in the-area of the plates 52, the amperage flowing through the solution will take the path of least resistance which is through the plates.

It may now be understood that any flow directing means may be employed which would raise the electrical resistance of the conductive solution in the vicinity of the plates 52. One such means would be to allow the conductive solution to spill over the top of the plates. This would result in high resistance of the solution at the top of the plates due to the thin conductive path at this point.

Therefore, in view of the above a definition of the fiow directing means may be any means located in the area of each of the plates which will result in an increase in the electrical resistance of the conductive solution adjacent to the plates.

Since the amperage flows through the plates 52, it may be seen that each of the plates acts as an electrical load in the circuit between the anode and the cathode, and thus there will be a voltage drop across each plate.

The specific example hereinbefore given resulted in solubilized cuprous chloride, thus the following plating process will be described so that the copper contained in that compound will electroplate onto the plates 52.

The voltage employed would be 9 volts and the number of plates (or loads) is selected at 15 so that the voltage drop across each plate will be approximately .5 volts. This results in a total voltage drop of 7.5 volts across the plates with the remaining 1.5 volts being dropped by the resistance of the conductive solution and back EMF.

.As is well known in the electroplating art, copper will plate out of solution onto a cathode when that cathode is electrically charged to approximately .5 volts.

As best seen in FIGS. 1 and 2 the plates 52 are removable so that when they become plated to a desired thickness, they can be replaced with unplated plates. The removable plates also allow the number of plates to be varied which would eifect the voltage drop. For example, by adding or removing a number of the plates 52, the voltage drop across each plate could be raised or lowered to suit the voltage per plate necessary to result in plating out of other metals. The following table is given to illustrate the various voltages per plate needed to electroplate specific metals:

Voltage drop per Solution Metal Voltage plate NH4C1 Copper... 9VDC .5 NH4C1 Nickel---- QVDG 2.0 NH401 Silver--- QVDC 1.0

8 basic chamber 14, and thus rendering them suitable for plating. The following table illustrates a few examples of this:

Less if copper plates are used.

It may be noted above that various compounds are employed in forming the conductive solution. One compound which appears frequently in the above table is ammonium nitrate (NH NO This compound will react by producing nitric acid with a production of free nitrus monoxide, and ammonium hydroxide. It is well known that the gaseous by-product, nitrus monoxide, would destroy the acidity of the solution contained in chamber 12 if it were not released or otherwise treated. In the interests of reclaiming and reusing the conductive solution, the nitrus monoxide will be treated as will hereinafter be described in detail to result in its becoming nitrogen dioxide.

Several factors play a part in determining the compound best suited for a particular situation. One important factor being economics, both in the expense of the initial purchase of the compound and its ability to be reclaimed and reused.

In general, the compound which is dissolved to form the conductive solution must be electrovalent so that electrolysis thereof results in its anion forming an acidic solution which is capable of solubilizing a particular desired metal or metal compound. The solubilizing is accomplished by either an oxidation-reduction process or by a chemical substitution so that the desired metal or metal compound is rendered soluble. The cation portion of the conductive solution must be capable of forming a basic solution which maintains the desired solubilized metal compound in solution, and must also be capable of complexing or chelating to render that compound suitable for electroplating. It may also be seen in the foregoing tables, and as previously described, 9' volts DC is used. It has been determined that this particular voltage value is ideal due to the rate of travel it induces on the ions. It should be noted however, that this voltage may be varied somewhat without adversely affecting the operation of the apparatus.

As hereinbefore described, free chlorine is produced in the acidic chamber 12 some of which may pass out of the solution as a gas. As is well known, chlorine gas is highly toxic and therefore must be controlled. The chlorine gas may be controlled by any of the well known methods such as by passing it through a solution of sodium hydroxide which will absorb the gas.

However, since it is desirable to reclaim and reuse the conductive solution, a more desirable controlling apparatus has been devised. This apparatus is defined as a. bombardment chamber 60 and is best seen in FIG. 2.

The bombardment chamber 60 includes a dome 62 which is designed to attach to the container 10 directly above the acidic chamber 12. As seen, the dome 62 seals the upper portion of the chamber 12. so that no chlorine gas or other gaseous by-products may escape into the atmosphere.

The dome 62 is provided with at least one ultraviolet lamp 64 or other suitable stimulating device such as an apparatus which produces an electric spark (not shown). The stimulating device raises the energy level of the free chlorine molecule to its highest possible energy level so that it will readily react with the ammonia contained within the ammoniacal solution being returned thereto from chamber 14 by the supply system 20. The reaction of the chlorine molecule, which has been raised to its highest possible energy level, with the ammonia produces ammonium chloride, thus reclaiming the spent conductive solution and returning it to its original state.

The first formula given below illustrates the reaction which would occur in the absence of the bombardment chamber, and the second illustrates the results achieved by use of the bombardment chamber:

As hereinbefore described, the ore containing slurry is supplied to the chamber 12 at specified predetermined intervals. These intervals are determined by the length of time necessary to solubilize the metal and metal compounds from a specific grade and quantity of ore. Once this interval has been determined for a specific ore, the spent ore contained in chamber 12 may be drained through a suitable valve 66 located in the bottom of that chamber, and a new supply of ore delivered thereto from the slurry tank 36.

The spent ore and the solution which is drained from chamber 12 may be routed to a settling tank (not shown) so that the conductive solution 18 may be returned to the supply system 20.

To speed up processing of the ore within the acidic chamber 12, an agitator device 68 may be provided. The agitator device 68 may take the form of a paddle wheel 70 formed to closely conform to the shape of the bottom surface of the chamber 12. The wheel 70 may be driven by a suitable driving mechanism such as an electric motor 72 mounted on the bombardment chamber 60. An elongated shaft 74 extends through a suitable seal 76, such as a carbon seal, and is coupled to support and rotatably drive the wheel 70.

Due to acid and presence of toxic gaseous by-products, such as chlorine, in the chamber 12, it is necessary that the wheel 70 and its drive shaft 74 be fabricated of materials which are inert. The same results could be accomplished by coating these components with suitable inert material such as PVC.

Agitation of the ore will continuously expose new surfaces of the ore to chemical action and thus speed up the solubilization process. This may be further enhanced by lining the bottom of the chamber 12 with a hard inert material 78 such as porcelain, and allowing a plurality of balls 80 of similar material to be moved over the surface 78 by action of the wheel 70.

While the principles of the invention have now been made clear in an illustrated embodiment, there will be immediately obvious to those skilled in the art, many modifications of structure, arrangements, proportions, the elements, materials, and components used in the practice of the invention, and otherwise, which are particularly adapted for specific environments and operation requirements without departing from those principles.

For example, the second chamber 12 as described and illustrated, is a single chamber. The apparatus of the present invention would function equally as well if a plurality of individual cells were employed. A large cell could be employed for precipitation purposes and a plurality of individual cells could be used for the mounting of the plates 52. These cells would be interconnected with suitable conduits for providing the necessary electric continuity and increased resistance of the conductive solution.

The appended claims are therefore intended to cover and embrace any such modifications within the limits only of the true spirit and scope of the invention.

What I claim is:

1. An apparatus for extracting ore comprising:

(a) a container formed of inert material having an inlet and an outlet, said container for containing a 10 conductive solution which is movable therethrough from the inlet to the outlet thereof;

(b) a permeable barrier for-med of inert material mounted in said container for forming a first chamber adjacent the inlet and a second chamber adjacent the outlet of said container, the first chamber of said container for receiving pulverized ore therein;

(c) an anode in the first chamber of said container;

(d) a cathode in the second chamber of said container, said cathode formed of a plurality of independently removably mounted metal plates positioned in spaced increments so that a first one of the plates is closest to said anode and a last one of the plates is farthest from said anode;

(e) a DC potential applied to said anode and to the last one of the plates of said cathode for electrolyzing the conductive solution when it is moving through said container for producing an acidic solution within the first chamber of said container which reacts with the ore when the ore is contained therein to form at least one metal compound solute, and for producing a basic solution in the second chamber of said container which will maintain the solubilized state of the metal compound solute and react therewith to render the metal contained therein electroplatable; and

(f) flow directing means acting on the conductive solution when the solution is in said container for increasing the electrical resistance of the conductive solution adjacent to each of the plates of said cathode to a level which is greater than the electrical resist ance of the plates to result in a voltage drop across each of the plates the value of which is selected to cause the metal contained in the metal compound solute to electroplate thereon.

2. An apparatus as claimed in claim 1 further comprising a supply system means by which the conductive solution is suplied to said container and moved therethrough, said supply system means coupled from the outlet of said container to the inlet thereof for initially providing the conductive solution and for recirculation and reclaiming thereof.

3. An apparatus as claimed in claim 2 wherein said supply system means comprises:

(a) a drain line coupled on one end thereof to the outlet of said container for withdrawing the conduc tive solution therefrom when the conductive solution is contained within said container;

(b) processing tank means coupled to the other end of said drain line for receiving and reclaiming the conductive solution when supplied thereto by said drain line, said processing tank means reclaiming the conductive solution by stripping any of the metal compound solutes remaining therein, said processing tank means having an outlet through which the stripped conductive solution is removable;

(c) a make-up reservoir coupled for receiving the stripped conductive solution from said processing tank means and making up any losses which may occur in the conductive solution during the usage thereof;

((1) flow switching means coupled to receive the conductive solution from said make-up reservoir and selectively direct the conductive solution to either of a pair of outlets provided on said flow switching means;

(e) a by-pass line coupled on one end thereof to one of the outlets of said flow switching means and coupled on the other end thereof to the inlet of said container for delivering the conductive solution, said by-pass line containing a flow control valve for regulating the rate of flow of the conductive solution; and

(f) an ore supplying line coupled to the other outlet of said flow switching means.

4. An apparatus as claimed in claim 3 wherein said ore supplying line comprises;

(a) a slurry tank in said ore supplying line for receiving said conductive solution from said flow switching means, said slurry tank having an outlet line coupled to the first chamber of said container;

(b) means for supplying said pulverized ore to said slurry tank for forming a slurry of said ore and said conductive solution; and

(c) pump means mounted into the outlet line of said slurry tank for delivering the slurry to said container.

5. An apparatus as claimed in claim 1 further comprising an agitator means mounted within the first chamber of said container.

6. An apparatus as claimed in claim 1 further comprising:

(a) a dome shaped structure attached to said container adjacent the first chamber thereof for containing gaseous by-products produced therein; and

(b) energy supplying means mounted within said domeshaped structure for raising the energy level of the gaseous by-products to their highest possible energy level to render these by-products capable of returning to their original chemical composition.

7. An apparatus as claimed in claim 6 wherein said energy supplying means includes at least one ultraviolet lamp.

. 8. An apparatus as claimed in claim 1 wherein said flow directing means is provided by each of the plates of said cathode having an off-center aperture formed therethrough, the plates being positioned in said container to locate the apertures thereof in a misaligned staggered relationship.

9. An apparatus for extracting copper from pulverized ore which contains copper compounds, said apparatus comprising:

(a) a container formed of inert material having an inlet and an outlet, said container for containing a conductive solution which is movable therethrough from the inlet to the outlet thereof;

(b) a permeable barrier formed of inert material mounted in said container for forming a first chamber adjacent the inlet and a second chamber adjacent the outlet of said container, the first chamber of said container adapted to receive the pulverized ore which contains copper compounds therein;

(c) an anode in the first chamber of said container;

(d) a cathode in the second chamber of said container, said cathode formed of a predetermined number of independently mounted plates positioned in spaced increments so that a first one of said plates is closest to said anode and a last one of said plates is farthest from said anode;

(e) a DC potential applied to said anode and to the last one of the plates of saidcathode for electrolyzing the conductive solution when it is moving through said container for producing an acidic solution within the first chamber of said container which is capable of reacting with the pulverized ore when the ore is contained therein to form a copper compound solute, the electrolyzing also producing a basic solution in the second chamber of said container which is capable of maintaining the solubilized state of the copper compound solute and reacting therewith to render the copper therein electroplatable; and

(f) flow directing means acting on the conductive solution when the solution is moving through said container for increasing the electrical resistance of the conductive solution to a level which is greater than the electrical resistance of the plates of said cathode to produce a voltage drop across each of the plates the value of which will cause electroplating thereon of the copper contained in the copper compound solute.

10. An apparatus as claimed in claim 9 wherein the conductive solution which is supplied to said container is formed by dissolving ammonium chloride in water so that electrolysis of the conductive solution will form hypochlorous acid and ammonium hydroxide.

11. An apparatus as claimed in claim 9 wherein the conductive solution which is supplied to said container is formed by dissolving ammonium nitrate in Water so the electrolysis of the conductive solutionwill form nitric acid and ammonium hydroxide.

12. An apparatus as claimed in claim 9 wherein the plates of said cathode are removable for allowing replacement thereof when the desired thickness of copper has been electroplated thereon and for allowing the number of the plates to be changed to adjust the voltage drop across each of the plates.

References Cited UNITED STATES PATENTS 841,720 1/1907 Ryan 204-234 1,137,874 5/1915 McCaskell 204-255 X 1,403,463 1/1922 Allingham 204-261 X 2,196,355 4/1940 Cremer 204-237 JOHN H. MACK, Primary Examiner D. R. VALENTINE, Assistant Examiner U.S. Cl. X.R. 

